Contractible spool



Aug. 7, 1934. $TE|N 1,969,281

CONTRAGTIBLE sPooL Filed Dec. 27, 1933" Patented Aug. 7, 1934 UNITEDSTATES CONTBACTIBLE SPOOL Alfred Ernst Stein, Saflle, Sweden ApplicationDecember 27, 1933, Serial No. 704,205 In Germany September 21, 1932 2Claims. (Cl. 242--110) This invention relates to contractible spools,that is, to spools which are capable of yielding to a radially directedpressure to allow for shrinkage of the thread wound.thereon as occurs inthe after treatment, more particularly the drying, of

artificial silk.

Contractible spools are already known whose casings are provided withradially movable members, which are pressed inwards by the shrinkage ofthe winding. These spools however, are costly to manufacture and allowonly a comparatively small decrease of the circumference.

Contractible spools are also known in which the casing consists of aslotted, springy sheet which rolls up during the shrinking of the threadwound thereon. Athough these spools are in themselves simple and cheaptheir manipulation is made diflicult in that special means, such asbands or the'like, must be usedto hold the spool in position when it isempty and prevent it being flung away from the quickly rotating spoolholder. Moreover, a uniform tension cannot be obtained with thesespools, particularly when used for winding strongly shrinking artificialsilk, as considerable force is required to overcome the springiness andfriction of the spool casing when it is rolled up or contracted.

Further, contractible spools are known in which the casing comprisesfour quadrants whose edges overlap so that they can slide upon oneanother to reduce the circumference as necessary. These spools, however,are difiicult to put on the spool holder and in addition, areunsatisfactory in that when removed the quadrants collapse and so nolonger hold the winding under tension.

According to the present invention the spool casing consists of anendless wire which is formed into a series of loops lying parallel tothe spool axis.

One embodiment of the invention is illustrated diagrammatically in theaccompanying drawing in which:

Figure 1 is a view of the complete spool and Figures 2 and 3 aredeveloped views of the spool casing when not under tension and whenunder tension respectively.

As will be seen from Figures 2 and 3 a contraction of the circumferenceof the spool of above 50% is possible.

With this construction very little effort is required to contract thespool as the pressure applied by the winding during shrinking occurs onthe arms of the loops a forming the spool casing so that a leverage isobtained when the loops are drawn together. There is also verylittlefriction to be overcome as the decrease in the circumference isdistributed over the entire circumference of the spool. .Thecompensation of tension attained is as complete as possible, if thewinding is to be kept under tension throughout the whole of theshrinking processes.

In order to avoid injury to the innermost layer of thread the spool amay be enclosed within an elastic sleeve b, and this sleeve may beprovided with perforations c or otherwise made pervious to fluids at thepart to be covered by the thread, the ends of the sleeve which are leftuncovered being made impervious to fluids.

The ends of the loops 0. can either lie in the extension of the spoolcasing or they may be partly flanged on the outside so as to formflange-like projections as rigid spools are usually provided with.

The diameter of these contractible spools is determined by the diameterof the spool holders with which they are to. be used. These spoolholders can be more easily made and manipulated than those for the rigidspools at present used as no springs, r'ubber blocks or other means arerequired for holding the spool fast to the spool holder.

Having now particularly described and ascertained the nature of my saidinvention and in what manner the same is' to be performed, I declarethat what I claim is:- 35

1. A contractible spool having a casing consisting of an endless wirewhich is formed into a series of loops lying parallel to the spool axis.

2. A contractible spool having a casing consisting of an endless wirewhich is formed into a series of loops lying parallel to the spool axis,and an elastic sleeve enclosing the casing and pervious to fluids at thepart to. be covered by the thread, the ends of the sleeve which are leftuncovered being impervious to fluids.

' ALFRED ERNST STEIN.

